954 EXPKJUMKNT STATION RECORD. 



4 geiieratiuiis and jjussilily ."J iirucliic-fd in a year, the insect brcetliiiK iiractically 

 continuously during the warm season." 



Seven itarasitic and six predaceous enemies are recorded, wliicli are said to 

 largely control the pests in ordinary years. A number of experiments with 

 insecticides indicate that a spray of ai'senate of lead used at the rate of 2 or .'{ 

 Ihs. in r>0 gals, of water, is the best remedy. 



Notes on the lesser clover-leaf beetle, C. O. Hoiomton (■/'nir. Econ. IJiil.. 

 I (tHOS), Ao. '). pp. 207-300). — PhutotiomuH nifjrirfistri.s is said to be quite 

 common in Delaware, where with P. punctiitus it at times does considerable 

 damage to clover. Biological notes arc given. 



Factors controlling' parasitism with special reference to the cotton boll 

 weevil, W. I). Pierck (Jour. Econ. Ent., I {1008), No. 5, pp. .iir)-.li,i).— In the 

 course of investigations made of the parasites of the boll weevil by the Bureau 

 of Entomology of this Department the author has had opiun'tunity to study the 

 factors intluencing parasitism in the wcovil.s. Sixteen factors of importance 

 are i)resented in addition to the eight considered by Marchal (10. S. R., 19, 

 p. lloD). 



A flea beetle attacking hops in British Columbia, H. J. Quayle (Jour. Econ. 

 Ent., 1 (1908), yo. 5, p. 323). — PsyUiodcs pmiclulata is repoi'ted to have been 

 seriously injuring hops in British Columbia during the past year or two. The 

 loss for 1908 in the Chilliwack and Agassiz valleys is estimated at about SO 

 per cent of the crop. 



Some insects injurious to truck crops. The leafhoppers of the sug-ar beet 

 and their relation to the "curly-leaf" condition, K. D. Ball (T. N. Dipt. 

 Agr., Bur. Ent. Bui. 66, pt. J/, pp. 33-52, pis. Jf). — In cooperation with the Bureau 

 of Entomology of this Department the author as entomologist of the Utah 

 Station has investigated an affection of the sugar beet knowm as "curly leaf" 

 or " blight." which occurs in the intermountain region, particularly in Utah and 

 Colorado. 



T'ntil ll»0.~» the condition had been .supposed to be due to some fungus or 

 bacterial disease, but in that year, w'hen an estimated loss of a half million 

 dollars resulted in T'tah from the curly leaf, the beet leaf hopper {Eutettix 

 icnclla) was noticed present in large numbers. 



The condition appears soon after an attack of the beet leaf hopper, a thicken- 

 ing of the smaller veins of the leaf taking place which gives the under surface 

 a thickened appearance. This is followed by a curling of the edge and a final 

 rolling nil of the leaf, the upper surface always being rolled in. This results 

 in the sending out of a large number of tibrous roots and in almost stoi)ping 

 the growth. In bad cases the beet slirivels and dies;, while in a few instances 

 there is a partial recovery and a new set of leaves, though the sugar content 

 remains low. 



Curly leaf appeared in cages in which beet leaf hoppers were introduced. 

 Whether or not the condition is entirely the result of the attacks of this pest 

 is siaid to be an open question. E. tencUa is apparently a native of the south- 

 western part of the United States, having been collected in Colorado, New 

 Mexico, Arizona, I'tah, Idaho, California, and Oi'egon. Leaving hibernation, it 

 appears in the fields about the time the beets are thinned and by the middle of 

 June is well distributed. At I.ehi. Utah, oviposition began late in June and 

 continued until late in August, each female depositing about 80 eggs. In cage 

 experiments the egg stage was between 13 and If) days and the larval stage 

 between 16 and 22 days. Nymphs that emerged from eggs the latter part of 

 July are said to have changed to adults some 20 days later. 



It is concluded that the severity of the condition is dependent upon the 

 number of insects present, upon the time of their appearance, upon the size of 



